[Doram]

Very weird. Any idea ? I have a video but i speak french hihi. But you can see the problem ^^

Does the water tank in the video have any water in it? (I looks empty, but the water LED is solid, so maybe I didn't see properly?)

I never used the filter so don't know for sure, but I think you need to soak it in water before using it. Did you do that? Maybe it had air in it and now you have an airlock in the system? Did you try filling the tank with water and running the pump (lifting the lever, without a blind basket) for 20-30 seconds to see if you can get rid of the air and water starts coming out of the group? If neither of these things help - wait for @DavecUK to rescue you.

 

[Doram]

Two more videos

1. No water tank :

In your first video just above (no water tank, and the tube is in a tub of water), water is coming out of the group, right? Did you try the same with a blind filter?

If no pressure is building up, this would indicate that the pump is not pushing hard enough to build pressure, or there is a leak of pressure somewhere, or the manometer isn't connected properly and not giving a correct read? Just guessing here. Let's see what @DavecUK and @MediumRoastSteam say.